////////////////////////////////////////////////////////////////////////////
//
//  Crytek Engine Source File.
//  Copyright (C), Crytek Studios, 2001-2005.
// -------------------------------------------------------------------------
//  File name:   TriMesh.h
//  Version:     v1.00
//  Created:     6/12/2004 by Timur.
//  Compilers:   Visual Studio.NET 2003
//  Description: 
// -------------------------------------------------------------------------
//  History:
//
////////////////////////////////////////////////////////////////////////////

#include "StdAfx.h"
#include "TriMesh.h"
#include "Objects\SubObjSelection.h"

//////////////////////////////////////////////////////////////////////////
CTriMesh::CTriMesh()
{
	pFaces = NULL;
	pVertices = NULL;
	pWSVertices = NULL;
	pUV = NULL;
	pColors = NULL;
	pEdges = NULL;
	pWeights = NULL;

	nFacesCount = 0;
	nVertCount = 0;
	nUVCount = 0;
	nEdgeCount = 0;

	selectionType = SO_ELEM_NONE;

	memset( m_streamSize,0,sizeof(m_streamSize) );
	memset( m_streamSel,0,sizeof(m_streamSel) );
	streamSelMask = 0;

	m_streamSel[VERTICES] = &vertSel;
	m_streamSel[EDGES] = &edgeSel;
	m_streamSel[FACES] = &faceSel;
}

//////////////////////////////////////////////////////////////////////////
CTriMesh::~CTriMesh()
{
	free(pFaces);
	free(pEdges);
	free(pVertices);
	free(pUV);
	free(pColors);
	free(pWSVertices);
	free(pWeights);
}

// Set stream size.
void CTriMesh::ReallocStream( int stream,int nNewCount )
{
	assert( stream >= 0 && stream < LAST_STREAM );
	if (stream < 0 || stream >= LAST_STREAM)
		return;
	if (m_streamSize[stream] == nNewCount)
		return; // Stream already have required size.
	void* pStream = 0;
	int nElementSize = 0;
	GetStreamInfo( stream,pStream,nElementSize );
	pStream = ReAllocElements(pStream,nNewCount,nElementSize);
	m_streamSize[stream] = nNewCount;

	switch (stream)
	{
	case VERTICES:
		pVertices = (CTriVertex*)pStream;
		nVertCount = nNewCount;
		vertSel.resize( nNewCount );
		break;
	case FACES:
		pFaces = (CTriFace*)pStream;
		nFacesCount = nNewCount;
		faceSel.resize(nNewCount);
		break;
	case EDGES:
		pEdges = (CTriEdge*)pStream;
		nEdgeCount = nNewCount;
		edgeSel.resize(nNewCount);
		break;
	case TEXCOORDS:
		pUV = (SMeshTexCoord*)pStream;
		nUVCount = nNewCount;
		break;
	case COLORS:
		pColors = (SMeshColor*)pStream;
		break;
	case WEIGHTS:
		pWeights = (float*)pStream;
		break;
	case LINES:
		pLines = (CTriLine*)pStream;
		break;
	case WS_POSITIONS:
		pWSVertices = (Vec3*)pStream;
		break;
	default:
		assert(0); // unknown stream.
	}
	m_streamSize[stream] = nNewCount;
}

// Set stream size.
void CTriMesh::GetStreamInfo( int stream,void* &pStream,int &nElementSize ) const
{
	assert( stream >= 0 && stream < LAST_STREAM );
	switch (stream)
	{
	case VERTICES:
		pStream = pVertices;
		nElementSize = sizeof(CTriVertex);
		break;
	case FACES:
		pStream = pFaces;
		nElementSize = sizeof(CTriFace);
		break;
	case EDGES:
		pStream = pEdges;
		nElementSize = sizeof(CTriEdge);
		break;
	case TEXCOORDS:
		pStream = pUV;
		nElementSize = sizeof(SMeshTexCoord);
		break;
	case COLORS:
		pStream = pColors;
		nElementSize = sizeof(SMeshColor);
		break;
	case WEIGHTS:
		pStream = pWeights;
		nElementSize = sizeof(float);
		break;
	case LINES:
		pStream = pLines;
		nElementSize = sizeof(CTriLine);
		break;
	case WS_POSITIONS:
		pStream = pWSVertices;
		nElementSize = sizeof(Vec3);
		break;
	default:
		assert(0); // unknown stream.
	}
}

//////////////////////////////////////////////////////////////////////////
void* CTriMesh::ReAllocElements(void *old_ptr,int new_elem_num, int size_of_element)
{
	return realloc(old_ptr,new_elem_num*size_of_element);
}

//////////////////////////////////////////////////////////////////////////
// Unshare all vertices and split on 3 arrays, positions/texcoords.
//////////////////////////////////////////////////////////////////////////
void CTriMesh::SetFromMesh( CMesh &mesh )
{
	bbox = mesh.m_bbox;

	int maxVerts = mesh.GetIndexCount();

	SetVertexCount( maxVerts );
	SetUVCount( maxVerts );
	if (mesh.m_pColor0)
		SetColorsCount( maxVerts );

	SetFacesCount( mesh.GetIndexCount() );

	int numv = 0;
	int numface = 0;
	for (int nSubset = 0; nSubset < mesh.GetSubSetCount(); nSubset++)
	{
		SMeshSubset &subset = mesh.m_subsets[nSubset];
		for (int i = subset.nFirstIndexId; i < subset.nFirstIndexId+subset.nNumIndices; i+=3)
		{
			CTriFace &face = pFaces[numface++];
			for (int j = 0; j < 3; j++)
			{
				int idx = mesh.m_pIndices[i+j];
				pVertices[numv].pos = mesh.m_pPositions ? mesh.m_pPositions[idx] : ToVec3(mesh.m_pPositionsF16[idx]);
				pWeights[numv] = 0.0f;
				pUV[numv] = mesh.m_pTexCoord[idx];
				if (mesh.m_pColor0)
					pColors[numv] = mesh.m_pColor0[idx];
				
				face.v[j] = numv;
				face.uv[j] = numv;
				face.n[j] = mesh.m_pNorms[idx];
				face.MatID = subset.nMatID;
				face.flags = 0;

				numv++;
			}
		}
	}
	SetFacesCount( numface );
	SharePositions();
	ShareUV();
	UpdateEdges();

	CalcFaceNormals();
}

/////////////////////////////////////////////////////////////////////////////////////
inline int FindVertexInHash( const Vec3 &vPosToFind, const CTriVertex *pVectors, std::vector<int> &hash,float fEpsilon )
{ 
	for (uint32 i=0; i < hash.size(); i++) 
	{
		const Vec3 &v0 = pVectors[hash[i]].pos;
		const Vec3 &v1 = vPosToFind;
		if (fabsf(v0.y-v1.y) < fEpsilon &&  fabsf(v0.x-v1.x) < fEpsilon &&  fabsf(v0.z-v1.z) < fEpsilon)
			return hash[i];
	}
	return -1;
}

/////////////////////////////////////////////////////////////////////////////////////
inline int FindTexCoordInHash( const SMeshTexCoord &coordToFind, const SMeshTexCoord *pCoords, std::vector<int> &hash,float fEpsilon )
{ 
	for (uint32 i=0; i < hash.size(); i++) 
	{
		const SMeshTexCoord &t0 = pCoords[hash[i]];
		const SMeshTexCoord &t1 = coordToFind;
		if (fabsf(t0.s-t1.s) < fEpsilon &&  fabsf(t0.t-t1.t) < fEpsilon)
			return hash[i];
	}
	return -1;
}


//////////////////////////////////////////////////////////////////////////
void CTriMesh::SharePositions()
{
	float fEpsilon = 0.0001f;
	float fHashScale = 256.0f / MAX(bbox.GetSize().GetLength(),fEpsilon);
	std::vector<int> arrHashTable[256];

	CTriVertex *pNewVerts = new CTriVertex[GetVertexCount()];
	SMeshColor *pNewColors = 0;
	if (pColors)
		pNewColors = new SMeshColor[GetVertexCount()];

	int nLastIndex = 0;
	for (int f = 0; f < GetFacesCount(); f++)
	{
		CTriFace &face = pFaces[f];
		for (int i = 0; i < 3; i++)
		{
			const Vec3 &v = pVertices[face.v[i]].pos;
			uint8 nHash = RoundFloatToInt( (v.x + v.y + v.z)*fHashScale );

			int find = FindVertexInHash( v, pNewVerts, arrHashTable[nHash], fEpsilon );
			if (find < 0)
			{
				pNewVerts[nLastIndex] = pVertices[face.v[i]];
				if (pColors)
					pNewColors[nLastIndex] = pColors[face.v[i]];
				face.v[i] = nLastIndex;
				// Reserve some space already.
				arrHashTable[nHash].reserve(100);
				arrHashTable[nHash].push_back(nLastIndex);
				nLastIndex++;
			}
			else
			{
				face.v[i] = find;
			}
		}
	}

	SetVertexCount(nLastIndex);
	memcpy( pVertices, pNewVerts, nLastIndex*sizeof(CTriVertex) );
	delete []pNewVerts;
	
	if (pColors)
	{
		SetColorsCount(nLastIndex);
		memcpy( pColors, pNewColors, nLastIndex*sizeof(SMeshColor) );
		delete []pNewColors;
	}
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::ShareUV()
{
	float fEpsilon = 0.0001f;
	float fHashScale = 256.0f;
	std::vector<int> arrHashTable[256];

	SMeshTexCoord *pNewUV = new SMeshTexCoord[GetUVCount()];

	int nLastIndex = 0;
	for (int f = 0; f < GetFacesCount(); f++)
	{
		CTriFace &face = pFaces[f];
		for (int i = 0; i < 3; i++)
		{
			const SMeshTexCoord &uv = pUV[face.uv[i]];
			uint8 nHash = RoundFloatToInt( (uv.s + uv.t)*fHashScale );

			int find = FindTexCoordInHash( uv, pNewUV, arrHashTable[nHash], fEpsilon );
			if (find < 0)
			{
				pNewUV[nLastIndex] = uv;
				face.uv[i] = nLastIndex;
				arrHashTable[nHash].reserve(100);
				arrHashTable[nHash].push_back(nLastIndex);
				nLastIndex++;
			}
			else
			{
				face.uv[i] = find;
			}
		}
	}

	SetUVCount(nLastIndex);
	memcpy( pUV, pNewUV, nLastIndex*sizeof(SMeshTexCoord) );
	delete []pNewUV;
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::CalcFaceNormals()
{
	for (int i = 0; i < nFacesCount; i++)
	{
		CTriFace &face = pFaces[i];
		Vec3 p1 = pVertices[face.v[0]].pos;
		Vec3 p2 = pVertices[face.v[1]].pos;
		Vec3 p3 = pVertices[face.v[2]].pos;
		face.normal = (p2-p1).Cross(p3-p1);
		face.normal.Normalize();
	}
}

#define TEX_EPS 0.001f
#define VER_EPS 0.001f

//////////////////////////////////////////////////////////////////////////
void CTriMesh::UpdateIndexedMeshFast( IIndexedMesh *pIndexedMesh )
{
	int maxVerts = GetFacesCount()*3;
	pIndexedMesh->SetIndexCount( maxVerts );

	bool *arrVertexTouched = new bool[maxVerts];
	memset( arrVertexTouched,0,sizeof(bool)*maxVerts );
	
	pIndexedMesh->SetVertexCount( maxVerts );
	pIndexedMesh->SetTexCoordsCount( maxVerts );
	if (pColors)
		pIndexedMesh->SetColorsCount( maxVerts );
	pIndexedMesh->SetIndexCount( maxVerts );

	CMesh &mesh = *pIndexedMesh->GetMesh();

	//////////////////////////////////////////////////////////////////////////
	// To find really used materials
	std::vector<int> usedMaterialIds;
	uint16 MatIdToSubset[MAX_SUB_MATERIALS];
	int nLastSubsetId = 0;
	memset(MatIdToSubset,0,sizeof(MatIdToSubset));
	//////////////////////////////////////////////////////////////////////////

	int numIndex = 0;
	int numv = GetVertexCount();
	for (int i = 0; i < nFacesCount; i++)
	{
		CTriFace &face = pFaces[i];
		// Remap new used material ID to index of chunk id.
		if (!MatIdToSubset[face.MatID])
		{
			MatIdToSubset[face.MatID] = 1 + nLastSubsetId++;
			usedMaterialIds.push_back(face.MatID); // Order of material ids in usedMaterialIds correspond to the indices of chunks.
		}

		for (int j = 0; j < 3; j++)
		{
			int fidx = face.v[j];
			if (!arrVertexTouched[fidx])
			{
				mesh.m_pPositions[fidx] = pVertices[fidx].pos;
				mesh.m_pNorms[fidx] = face.n[j];
				mesh.m_pTexCoord[fidx] = pUV[face.uv[j]];
				if (pColors)
					mesh.m_pColor0[fidx] = pColors[fidx];

				mesh.m_pIndices[numIndex] = fidx;
				arrVertexTouched[fidx] = true;
			}
			else
			{
				// Check if we can share this vertex.
				const SMeshTexCoord &uv1 = mesh.m_pTexCoord[fidx];
				const SMeshTexCoord &uv2 = pUV[face.uv[j]];
				if (mesh.m_pNorms[fidx].IsEquivalent(face.n[j],VER_EPS) && (fabs(uv1.s-uv2.s) < TEX_EPS && fabs(uv1.t - uv2.t) < TEX_EPS))
				{
					mesh.m_pIndices[numIndex] = fidx;
				}
				else
				{
					// Must add a new vertex.
					mesh.m_pPositions[numv] = pVertices[fidx].pos;
					mesh.m_pNorms[numv] = face.n[j];
					mesh.m_pTexCoord[numv] = pUV[face.uv[j]];
					if (pColors)
						mesh.m_pColor0[numv] = pColors[fidx];
					mesh.m_pIndices[numIndex] = numv;
					numv++;
				}
			}
			numIndex++;
		}
	}

	pIndexedMesh->SetSubSetCount(usedMaterialIds.size());
	for (int i = 0; i < usedMaterialIds.size(); i++)
	{
		pIndexedMesh->SetSubsetMaterialId(i, usedMaterialIds[i]);
	}

	assert( numv <= maxVerts );

	pIndexedMesh->SetVertexCount( numv );
	pIndexedMesh->SetTexCoordsCount( numv );
	if (pColors)
		pIndexedMesh->SetColorsCount( numv );
	pIndexedMesh->SetIndexCount( numIndex );

	delete []arrVertexTouched;
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::UpdateIndexedMesh( IIndexedMesh *pIndexedMesh )
{
	int maxVerts = GetFacesCount()*3;
	pIndexedMesh->SetIndexCount( maxVerts );

	bool *arrVertexTouched = new bool[maxVerts];
	memset( arrVertexTouched,0,sizeof(bool)*maxVerts );

	pIndexedMesh->SetVertexCount( maxVerts );
	pIndexedMesh->SetTexCoordsCount( GetUVCount() );
	if (pColors)
		pIndexedMesh->SetColorsCount( maxVerts );
	pIndexedMesh->SetFacesCount( GetFacesCount() );

	CMesh &mesh = *pIndexedMesh->GetMesh();
	
	// copy UV coords.
	memcpy( mesh.m_pTexCoord,pUV,nUVCount*sizeof(SMeshTexCoord) );

	//////////////////////////////////////////////////////////////////////////
	// To find really used materials
	std::vector<int> usedMaterialIds;
	uint16 MatIdToSubset[MAX_SUB_MATERIALS];
	int nLastSubsetId = 0;
	memset(MatIdToSubset,0,sizeof(MatIdToSubset));
	//////////////////////////////////////////////////////////////////////////

	int numIndex = 0;
	int numv = GetVertexCount();
	for (int i = 0; i < nFacesCount; i++)
	{
		CTriFace &face = pFaces[i];
		SMeshFace &meshFace = mesh.m_pFaces[i];
		// Remap new used material ID to index of chunk id.
		if (!MatIdToSubset[face.MatID])
		{
			MatIdToSubset[face.MatID] = 1 + nLastSubsetId++;
			usedMaterialIds.push_back(face.MatID); // Order of material ids in usedMaterialIds correspond to the indices of chunks.
		}
		meshFace.nSubset = MatIdToSubset[face.MatID]-1;

		for (int j = 0; j < 3; j++)
		{
			int fidx = face.v[j];
			if (!arrVertexTouched[fidx])
			{
				mesh.m_pPositions[fidx] = pVertices[fidx].pos;
				mesh.m_pNorms[fidx] = face.n[j];
				if (pColors)
					mesh.m_pColor0[fidx] = pColors[fidx];
				arrVertexTouched[fidx] = true;
			}
			else
			{
				// Check if we can share normal of this vertex.
				if (!mesh.m_pNorms[fidx].IsEquivalent(face.n[j],VER_EPS))
				{
					// Must add a new vertex.
					mesh.m_pPositions[numv] = pVertices[fidx].pos;
					mesh.m_pNorms[numv] = face.n[j];
					if (pColors)
						mesh.m_pColor0[numv] = pColors[fidx];
					fidx = numv;
					numv++;
				}
			}
			meshFace.t[j] = face.uv[j];
			meshFace.v[j] = fidx;
		}
	}

	CalcBBox();

	pIndexedMesh->SetSubSetCount(usedMaterialIds.size());
	for (int i = 0; i < usedMaterialIds.size(); i++)
	{
		pIndexedMesh->SetSubsetMaterialId(i, usedMaterialIds[i]);
	}

	pIndexedMesh->SetBBox( bbox );
	pIndexedMesh->SetVertexCount( numv );
	if (pColors)
		pIndexedMesh->SetColorsCount( numv );
	pIndexedMesh->Optimize();

	delete []arrVertexTouched;
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::CalcBBox()
{
	AABB bbox;
	bbox.Reset();
	for (int i = 0; i < GetVertexCount(); i++)
	{
		bbox.Add( pVertices[i].pos );
	}
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::CopyStream( CTriMesh &fromMesh,int stream )
{
	void *pTrgStream = 0;
	void *pSrcStream = 0;
	int nElemSize = 0;
	fromMesh.GetStreamInfo( stream,pSrcStream,nElemSize );
	if (pSrcStream)
	{
		ReallocStream( stream,fromMesh.GetStreamSize(stream) );
		GetStreamInfo( stream,pTrgStream,nElemSize );
		memcpy( pTrgStream,pSrcStream,nElemSize*fromMesh.GetStreamSize(stream) );
	}
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::Copy( CTriMesh &fromMesh,int nCopyFlags )
{
	streamSelMask = fromMesh.streamSelMask;

	if (nCopyFlags & COPY_VERTICES)
		CopyStream( fromMesh,VERTICES );
	if (nCopyFlags & COPY_FACES)
		CopyStream( fromMesh,FACES );
	if (nCopyFlags & COPY_EDGES)
		CopyStream( fromMesh,EDGES );
	if (nCopyFlags & COPY_TEXCOORDS)
		CopyStream( fromMesh,TEXCOORDS );
	if (nCopyFlags & COPY_COLORS)
		CopyStream( fromMesh,COLORS );
	if (nCopyFlags & COPY_WEIGHTS)
		CopyStream( fromMesh,WEIGHTS );
	if (nCopyFlags & COPY_LINES)
		CopyStream( fromMesh,LINES );
	
	if (nCopyFlags & COPY_VERT_SEL)
		vertSel = fromMesh.vertSel;
	if (nCopyFlags & COPY_EDGE_SEL)
		edgeSel = fromMesh.edgeSel;
	if (nCopyFlags & COPY_FACE_SEL)
		faceSel = fromMesh.faceSel;

}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::UpdateEdges()
{
	SetEdgeCount( GetFacesCount()*3 );

	std::map<CTriEdge,int> edgemap;
	
	int nEdges = 0;
	for (int i = 0; i < GetFacesCount(); i++)
	{
		CTriFace &face = pFaces[i];
		for (int j = 0; j < 3; j++)
		{
			int v0 = j;
			int v1 = (j!=2) ? j+1 : 0;
			CTriEdge edge;
			edge.flags = 0;

			// First vertex index must always be smaller.
			if (face.v[v0] < face.v[v1])
			{
				edge.v[0] = face.v[v0];
				edge.v[1] = face.v[v1];
			}
			else
			{
				edge.v[0] = face.v[v1];
				edge.v[1] = face.v[v0];
			}
			edge.face[0] = i;
			edge.face[1] = -1;
			int nedge = stl::find_in_map(edgemap,edge,-1 );
			if (nedge >= 0)
			{
				// Assign this face as a second member of the edge.
				if (pEdges[nedge].face[1] < 0)
					pEdges[nedge].face[1] = i;

				face.edge[j] = nedge;
			}
			else
			{
				edgemap[edge] = nEdges;
				pEdges[nEdges] = edge;
				face.edge[j] = nEdges;
				nEdges++;
			}
		}
	}

	SetEdgeCount( nEdges );
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::SoftSelection( const SSubObjSelOptions &options )
{
	int i;
	int nVerts = GetVertexCount();
	CTriVertex *pVerts = pVertices;

	for (i = 0; i < nVerts; i++)
	{
		if (pWeights[i] == 1.0f)
		{
			const Vec3 &vp = pVerts[i].pos;
			for (int j = 0; j < nVerts; j++)
			{
				if (pWeights[j] != 1.0f)
				{
					if (vp.IsEquivalent(pVerts[j].pos,options.fSoftSelFalloff))
					{
						float fDist = vp.GetDistance(pVerts[j].pos);
						if (fDist < options.fSoftSelFalloff)
						{
							float fWeight = 1.0f - (fDist / options.fSoftSelFalloff);
							if (fWeight > pWeights[j])
							{
								pWeights[j] = fWeight;
							}
						}
					}
				}
			}
		}
	}
}

//////////////////////////////////////////////////////////////////////////
bool CTriMesh::UpdateSelection()
{
	bool bAnySelected = false;
	if (selectionType == SO_ELEM_VERTEX)
	{
		for (int i = 0; i < GetVertexCount(); i++)
		{
			if (vertSel[i])
			{
				bAnySelected = true;
				pWeights[i] = 1.0f;
			}
			else
				pWeights[i] = 0;
		}
	}
	if (selectionType == SO_ELEM_EDGE)
	{
		// Clear weights.
		for (int i = 0; i < GetVertexCount(); i++)
			pWeights[i] = 0;

		for (int i = 0; i < GetEdgeCount(); i++)
		{
			if (edgeSel[i])
			{
				bAnySelected = true;
				CTriEdge &edge = pEdges[i];
				for (int j = 0; j < 2; j++)
					pWeights[edge.v[j]] = 1.0f;
			}
		}
	}
	else if (selectionType == SO_ELEM_FACE)
	{
		// Clear weights.
		for (int i = 0; i < GetVertexCount(); i++)
			pWeights[i] = 0;

		for (int i = 0; i < GetFacesCount(); i++)
		{
			if (faceSel[i])
			{
				bAnySelected = true;
				CTriFace &face = pFaces[i];
				for (int j = 0; j < 3; j++)
					pWeights[face.v[j]] = 1.0f;
			}
		}
	}
	return bAnySelected;
}


//////////////////////////////////////////////////////////////////////////
bool CTriMesh::ClearSelection()
{
	bool bWasSelected = false;
	// Remove all selections.
	int i;
	for (i = 0; i < GetVertexCount(); i++)
	{
		pWeights[i] = 0;
	}
	streamSelMask = 0;
	for (int i = 0; i < LAST_STREAM; i++)
	{
		if (m_streamSel[i] && !m_streamSel[i]->is_zero())
		{
			bWasSelected = true;
			m_streamSel[i]->clear();
		}
	}
	return bWasSelected;
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::GetEdgesByVertex( MeshElementsArray &inVertices,MeshElementsArray &outEdges )
{
	// Brute force algorithm using binary search.
	// for every edge check if edge vertex is inside inVertices array.
	std::sort( inVertices.begin(),inVertices.end() );
	for (int i = 0; i < GetEdgeCount(); i++)
	{
		if (stl::binary_find(inVertices.begin(),inVertices.end(),pEdges[i].v[0]) != inVertices.end())
			outEdges.push_back(i);
		else if (stl::binary_find(inVertices.begin(),inVertices.end(),pEdges[i].v[1]) != inVertices.end())
			outEdges.push_back(i);
	}
}

//////////////////////////////////////////////////////////////////////////
void CTriMesh::GetFacesByVertex( MeshElementsArray &inVertices,MeshElementsArray &outFaces )
{
	// Brute force algorithm using binary search.
	// for every face check if face vertex is inside inVertices array.
	std::sort( inVertices.begin(),inVertices.end() );
	for (int i = 0; i < GetFacesCount(); i++)
	{
		if (stl::binary_find(inVertices.begin(),inVertices.end(),pFaces[i].v[0]) != inVertices.end())
			outFaces.push_back(i);
		else if (stl::binary_find(inVertices.begin(),inVertices.end(),pFaces[i].v[1]) != inVertices.end())
			outFaces.push_back(i);
		else if (stl::binary_find(inVertices.begin(),inVertices.end(),pFaces[i].v[2]) != inVertices.end())
			outFaces.push_back(i);
	}
}
